1. Field of the Invention
The invention relates to a battery protection structure for protecting a battery placed below the floor panel in the body of an automobile, from deformation of the body's side portion in a lateral collision.
2. Description of Related Art
In the floor structure for an electric automobile disclosed in Japanese Patent Application Publication No. 7-156831 (JP 7-156831 A), a side member is mounted on the lower surface of the side portion of a floor panel. A battery frame installed with a battery is mounted on the side member. An outrigger is mounted between a side sill (rocker) provided at the side edge of the floor panel and the side member. The outrigger is provided with an extended portion that is adjacent to the outside wall of the battery frame.
The floor structure mentioned above uses the outrigger to keep the outside wall of the battery frame from collapsing in a lateral collision, thereby preventing damage to the battery. Also, the floor structure absorbs impact energy by causing the body's side portion such as the side sill and the outrigger to undergo crushing deformation.
With the floor structure mentioned above, in cases such as when a high capacity, large sized battery is required or when the width dimension of the vehicle is small, it is difficult to keep the amount of deformation (deformation stroke) of the body's side portion in a lateral collision to an extent that can avoid interference between the body's side portion and the battery. In such cases, interference between the body's side portion and the battery can be easily avoided by reducing the amount of deformation of the body's side portion by increasing the strength and rigidity of the body's side portion. However, such a configuration leads to an increase in the mass and cost of the body.